1. Field of the Invention
The present invention is a mode setting method and a system including a PCI bus in the hot plug of a PCI device.
2. Description of the Related Art
A system including a PCI bus according to the present invention will be described below.
FIG. 7 is a block diagram of the system including a PCI bus according to the present invention, and FIG. 8 is a block diagram of a PCI control circuit according to the present invention.
As shown in FIG. 7, the system including a PCI bus according to the present invention does not include a config read command issuing circuit and a hot add control circuit but includes a processor 101, a north bridge 102, a south bridge 104 including a PCI control circuit 110, a PCI slot 105, and a firmware 103.
As shown in FIG. 8, the PCI control circuit according to the present invention does not include a config access retry control circuit but includes a PCI bus control circuit 201 and a mode register 202 (Japanese Unexamined Patent Application Publication Nos. 2000-276258, 2003-046511, 2006-146921, and h11-175456).
The hot-adding of a PCI device is notified only to an OS (operating system) or a hot plug driver from the south bridge, but the hot-adding can not be notified to the firmware 103 without modifying the OS or the hot plug driver.
The above-mentioned hot add method in the system according to the present invention has the following problems.
First problem is that since it is difficult to request to modify a OS or an open hot plug driver or to make a hot plug driver by a user, it is not possible to support a platform unique function for a PCI device that is hot-added during the system is operated, though it is possible to support the platform unique function for the PCI device that has been incorporated into the system when it's booted.
Second problem is that hardware and firmware cannot determine the timing when config access to the hot-added PCI device is available and thus cannot read a vendor ID or a device ID of the hot-added PCI device.
Third problem is that, config access cannot be interrupted by hardware or firmware because if the config access from hardware or firmware competes with the config access from the processor, some PCI devices cannot operate and be controlled.
For these reasons, in a system capable of hot-adding a PCI device, a mode setting method and a system including a PCI bus in the hot plug of a PCI device, which is capable of supporting the platform unique function for a PCI device that is hot-added during the system is operated by allowing to notify the hot-adding of a PCI device to firmware that controls the platform unique function and by allowing the firmware to easily recognize a vendor ID and a device ID of the hot-added PCI device.